Teach you to use the depth of field effect of digital camera flexibly.

How to use digital to exert the effect of depth of field

Now many digital cameras are equipped with manual function. If you buy it, you need to know how to operate it. If you only use automatic shooting, it is a waste of money to buy these functions. In order to let everyone use the DC manual function in their hands to shoot people in an instant, we will teach you some basic photography theories in simple terms, coupled with actual combat effects, to ensure that you can learn to play. In this issue, let's start with the more introductory depth of field effect.

When shooting portraits, you can use shallow depth of field to highlight the subject.

What is depth of field?

I believe many girls have tried to find someone to take some so-called "salon" photos in the park. Only when they see that they are sharp in the photo and the background is hazy, coupled with the ingenious effect of soft-light photos, E rushes to C, will they think that the photographer is very professional. In fact, the effect of "people with clear background" is only the principle of camera depth of field. What is depth of field?

As we all know, cameras can only shoot after focusing. Theoretically, only the accurately focused part (focus) of a photo is clear, and the scenery before and after focusing will be blurred because of out-of-focus. However, based on the lens, shooting distance and other factors, there will still be a distance before and after focusing, which can clearly show the scene without falling into a blurred area. This clear range is called depth of field.

Three methods of controlling depth of field

Method 1: pore size

Based on physical laws, the depth of field of photos taken with large aperture (small F value) will be shallow, and the depth of field of photos taken with small aperture (large F value) will be deep. For example, photos taken with f/2.8 aperture must have a shallower depth of field than those taken with f/8. If everyone's DC has aperture priority or manual exposure function, you can control the depth of field by controlling the aperture size.

The aperture of DC in the market is generally larger than that of traditional cameras. For example, the lens of Olympus Camedia C-4040Z has a large aperture of f/ 1.8, while the lens of f/2.0 is more common, such as Casio QV-4000, Canon PowerShot G2, Sony CyberShot DSC-S85, etc. When buying digital cameras, the maximum aperture of the lens is one of the important considerations, because the aperture can be reduced at will, but the maximum light. On the left, almost all DC lenses are engraved with the maximum aperture value. On the right, the aperture of Olympus Camedia C-4040Z is as large as f/ 1.8.

Method 2: focal length

I saw the master who took photos of girls every day. The photos he took were one foot long. Do you know why? It turns out that the lens with long focal length is easier to get the effect of shallow depth of field, and girls generally like it. The longer the focal length, the shallower the depth of field; Conversely, the shorter the focus lens, the deeper the depth of field. Now, DC is usually equipped with a wide-angle to medium-long focal length zoom lens (zoom lens). As long as you use zoom, you can easily control the depth of field, and the effect is generally obvious.

The number displayed in front of the lens is the actual focal length. Because the CCD size of each DC is different, each digital camera will explain what the lens shooting effect is equivalent to the focal length of 135 film camera, which is called equivalent focal length.

Generally, DC lenses on the market have three times optical zoom, and the longest focal length can reach 85 to105 mm. Some special models have eight to ten times optical zoom, so it is easy to obtain shallow depth of field effect. However, due to the different CCD sizes of DC photosensitive chips, the depth of field is different even under the same focal length, which will be discussed in depth in the future.

Method 3: Shooting distance

The most powerful thing about DC is that the focal length is particularly short recently. The nearest focal length of an ordinary traditional lens is 20 to 30cm, but the nearest focal length of DC is 0cm. For example, Canon S3 and S2 are both record holders. The closer the shooting distance is, the shallower the depth of field will be, so the depth of field of a close-up or macro photo may be only one or two microns near the focus, and the scenery farther away is already blurred.

When shooting at the nearest focal length, the shallow depth of field effect is very special.

The Classic Application of Shallow Depth of Field-Portrait Photography

The effect of shallow depth of field is most commonly used to extract the subject from the messy background, which will make it easier to take a portrait, because the photographer only needs to capture the expression and action of the protagonist, and does not have to worry too much about the background processing. However, the common three-fold optical zoom DC depth of field on the market is not shallow enough, so using this portrait shooting technique requires at least eight to ten times optical zoom.

A Classic Application Example of Depth of Field —— Landscape Photography

When shooting magnificent scenery and buildings, it is often required that the photos are clear everywhere and need a deep depth of field. When shooting, zoom the lens to the shortest, adjust the aperture to the thinnest (DC is usually f/8), and then use a lower shooting angle, the effect will generally not be too bad. Note that at present, the shortest focal length of DC is generally 35mm, and only a few DCs such as Nikon CoolPix 5000 and Kodak DSC 4800 can reach 28mm.

Shooting the scenery with the widest focal length, the scene is more than ten minutes away from the lens, and any place in the photo is almost imperceptible.